Methods of increasing the fire and explosion safety in tank battery

According to various estimates from 50 to 90 million tons of hydrocarbons are released into the atmosphere annually. Significant air pollution with oil vapors is done during filling and draining of tanks – the so-called tanks’ “breathing”. In this case 75% of the loss comes from vaporization, and only 25% – from accidents and leaks. In many production and climatic situations maximum losses occur as a result of “small breaths” or weathering of gas space. However fire-prone gas pollution occurs mostly as a result of “big breaths” when there is a brief but powerful emission of vapors which poses a risk of an emergency in the tank battery. For the purposes of improving secure exploitation in the vertical steel cylinder tanks, pontoons have gained wide application. Despite all advantages of pontoons, operation practice has shown that emergencies caused by their jamming, warps, fall and even destruction are rather frequent. The reason for such situations is often a discharge of gas plug formed on elevated areas of the pipeline route, or during repair works, down to a pressure close to atmospheric. The article contains the results of industrial tests of aluminum pontoons, produced by two different manufacturers, in order to assess the reliability of pontoon designs when exposed to an air cap. Despite the high efficiency of pontoons, they have certain negative features. When operating pontoons, fire explosive hydrocarbons concentrate in the space above the pontoons. The noted disadvantages of pontoons force to develop new more effective ways to reduce emissions and enhance fire explosion safety of the tank battery. Based on the analysis of Russian patents, we considered methods of increasing reliability of the pontoon structures and a device for emission reduction and enhancing fire explosion safety of the tank battery – “breathing” gas chamber. This device can reduce the loss of oil and oil products from evaporation in tanks and minimizes explosive, environmental and economic risks.